Estimation of the tensile strength of European beech timber boards based on density, dynamic modulus of elasticity and local fibre orienation

A newly developed non-contact method to identify and quantify the fibre orientation in European beech wood (Fagus sylvatica L.) was used to estimate the tensile strength of timber boards. The developed approach is based on an automated visual analysis of the spindle pattern formed by the medullary rays, also called wood rays. Each spindle is identified using digital image feature-extraction techniques, its position and orientation is determined, and the average fibre orientation in predefined subsets is calculated. Subsequently performed tension tests on European beech timber boards showed that the estimation of the tensile strength based on the local fibre orientation is much more accurate and precise than the estimation based on other common strength and stiffness indicators